如何与实体框架数据模型设计者进行简单的连接？

Question

我试过这个： http://channel9.msdn.com/posts/RobBagby/deCast-Entity-Framework-Modeling-Implementing-Entity-Splitting/Default.aspx?wa=wsignin1.0

...使用Employee和Contact表，使用Codeplex中的Northwind示例数据库。我想创建一个EmployeeContact实体，它基本上从Contact中提取FirstName和LastName列。因此，我将这些属性和ContactID属性从Contact实体复制并粘贴到Employee实体。我映射了所有这些，但我现在得到一个关于映射EmployeeID属性的错误：

“错误3024：从第389行开始映射片段时出现问题：必须为EntitySet Employees的所有关键属性（Employees.EmployeeID）指定映射。”

就此而言，我如何让VS向我展示映射文件的标记，而不是向我展示设计师？至少可能然后我可以开始看到错误的来源，因为它引用了特定的行号。

映射此属性，映射详细信息视图显示从表列到同名实体属性的赋值，该属性已经为我生成。我花了很多时间来达到这一点，并且创建通常简单的连接是非常令人沮丧的。我讨厌想象一下，做一些甚至稍微复杂一点的问题。

我确信有人会建议我使用LINQ，但我认为实体框架的全部目的是为了让你更多地考虑数据的含义而不是关系结构？换句话说，每次你想要一组简单的数据时都不必进行大量的连接。

提前致谢。

这是我的edmx文件，我已经删除了映射部分以尝试将其编译：

<?xml version="1.0" encoding="utf-8"?>
<edmx:Edmx Version="1.0" xmlns:edmx="http://schemas.microsoft.com/ado/2007/06/edmx">
  <!-- EF Runtime content -->
  <edmx:Runtime>
    <!-- SSDL content -->
    <edmx:StorageModels>
      <Schema Namespace="AdventureWorksModel.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2006/04/edm/ssdl">
        <EntityContainer Name="AdventureWorksModelStoreContainer">
          <EntitySet Name="Employee" EntityType="AdventureWorksModel.Store.Employee" store:Type="Tables" Schema="HumanResources" />
          <EntitySet Name="Contact" EntityType="AdventureWorksModel.Store.Contact" Schema="Person" store:Type="Tables" />
          <AssociationSet Name="FK_Employee_Contact_ContactID" Association="AdventureWorksModel.Store.FK_Employee_Contact_ContactID">
            <End EntitySet="Contact" Role="Contact" />
            <End EntitySet="Employee" Role="Employee" />
          </AssociationSet>
          <AssociationSet Name="FK_Employee_Employee_ManagerID" Association="AdventureWorksModel.Store.FK_Employee_Employee_ManagerID">
            <End Role="Employee" EntitySet="Employee" />
            <End Role="Employee1" EntitySet="Employee" />
          </AssociationSet>
        </EntityContainer>
        <EntityType Name="Employee">
          <Key>
            <PropertyRef Name="EmployeeID" />
          </Key>
          <Property Name="EmployeeID" Type="int" Nullable="false" StoreGeneratedPattern="Identity" />
          <Property Name="NationalIDNumber" Type="nvarchar" Nullable="false" MaxLength="15" />
          <Property Name="ContactID" Type="int" Nullable="false" />
          <Property Name="LoginID" Type="nvarchar" Nullable="false" MaxLength="256" />
          <Property Name="ManagerID" Type="int" />
          <Property Name="Title" Type="nvarchar" Nullable="false" MaxLength="50" />
          <Property Name="BirthDate" Type="datetime" Nullable="false" />
          <Property Name="MaritalStatus" Type="nchar" Nullable="false" MaxLength="1" />
          <Property Name="Gender" Type="nchar" Nullable="false" MaxLength="1" />
          <Property Name="HireDate" Type="datetime" Nullable="false" />
          <Property Name="SalariedFlag" Type="bit" Nullable="false" />
          <Property Name="VacationHours" Type="smallint" Nullable="false" />
          <Property Name="SickLeaveHours" Type="smallint" Nullable="false" />
          <Property Name="CurrentFlag" Type="bit" Nullable="false" />
          <Property Name="rowguid" Type="uniqueidentifier" Nullable="false" />
          <Property Name="ModifiedDate" Type="datetime" Nullable="false" />
        </EntityType>
        <EntityType Name="Contact">
          <Key>
            <PropertyRef Name="ContactID" />
          </Key>
          <Property StoreGeneratedPattern="Identity" Name="ContactID" Nullable="false" Type="int" />
          <Property Name="NameStyle" Nullable="false" Type="bit" />
          <Property Name="Title" MaxLength="8" Type="nvarchar" />
          <Property Name="FirstName" Nullable="false" MaxLength="50" Type="nvarchar" />
          <Property Name="MiddleName" MaxLength="50" Type="nvarchar" />
          <Property Name="LastName" Nullable="false" MaxLength="50" Type="nvarchar" />
          <Property Name="Suffix" MaxLength="10" Type="nvarchar" />
          <Property Name="EmailAddress" MaxLength="50" Type="nvarchar" />
          <Property Name="EmailPromotion" Nullable="false" Type="int" />
          <Property Name="Phone" MaxLength="25" Type="nvarchar" />
          <Property Name="PasswordHash" Nullable="false" MaxLength="128" Type="varchar" />
          <Property Name="PasswordSalt" Nullable="false" MaxLength="10" Type="varchar" />
          <Property Name="AdditionalContactInfo" Type="xml" />
          <Property Name="rowguid" Nullable="false" Type="uniqueidentifier" />
          <Property Name="ModifiedDate" Nullable="false" Type="datetime" />
        </EntityType>
        <Association Name="FK_Employee_Contact_ContactID">
          <End Type="AdventureWorksModel.Store.Contact" Multiplicity="1" Role="Contact" />
          <End Type="AdventureWorksModel.Store.Employee" Multiplicity="*" Role="Employee" />
          <ReferentialConstraint>
            <Principal Role="Contact">
              <PropertyRef Name="ContactID" />
            </Principal>
            <Dependent Role="Employee">
              <PropertyRef Name="ContactID" />
            </Dependent>
          </ReferentialConstraint>
        </Association>
        <Association Name="FK_Employee_Employee_ManagerID">
          <End Role="Employee" Type="AdventureWorksModel.Store.Employee" Multiplicity="0..1" />
          <End Role="Employee1" Type="AdventureWorksModel.Store.Employee" Multiplicity="*" />
          <ReferentialConstraint>
            <Principal Role="Employee">
              <PropertyRef Name="EmployeeID" />
            </Principal>
            <Dependent Role="Employee1">
              <PropertyRef Name="ManagerID" />
            </Dependent>
          </ReferentialConstraint>
        </Association>
      </Schema>
    </edmx:StorageModels>
    <!-- CSDL content -->
    <edmx:ConceptualModels>
      <Schema Namespace="AdventureWorksModel" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation" xmlns="http://schemas.microsoft.com/ado/2006/04/edm">
        <EntityContainer Name="AdventureWorksEntities">
          <EntitySet Name="EmployeeContacts" EntityType="AdventureWorksModel.EmployeeContact" />
          </EntityContainer>
        <EntityType Name="EmployeeContact">
          <Key>
            <PropertyRef Name="ContactID" />            
          </Key>
          <Property Name="EmployeeID" Type="Int32" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
          <Property Name="NationalIDNumber" Type="String" Nullable="false" MaxLength="15" Unicode="true" FixedLength="false" />
          <Property Name="LoginID" Type="String" Nullable="false" MaxLength="256" Unicode="true" FixedLength="false" />
          <Property Name="Title" Type="String" Nullable="false" MaxLength="50" Unicode="true" FixedLength="false" />
          <Property Name="BirthDate" Type="DateTime" Nullable="false" />
          <Property Name="MaritalStatus" Type="String" Nullable="false" MaxLength="1" Unicode="true" FixedLength="true" />
          <Property Name="Gender" Type="String" Nullable="false" MaxLength="1" Unicode="true" FixedLength="true" />
          <Property Name="HireDate" Type="DateTime" Nullable="false" />
          <Property Name="SalariedFlag" Type="Boolean" Nullable="false" />
          <Property Name="VacationHours" Type="Int16" Nullable="false" />
          <Property Name="SickLeaveHours" Type="Int16" Nullable="false" />
          <Property Name="CurrentFlag" Type="Boolean" Nullable="false" />
          <Property Name="rowguid" Type="Guid" Nullable="false" />
          <Property Name="ModifiedDate" Type="DateTime" Nullable="false" />
          <Property Type="String" Name="FirstName" Nullable="false" MaxLength="50" FixedLength="false" Unicode="true" />
          <Property Type="String" Name="MiddleName" MaxLength="50" FixedLength="false" Unicode="true" />
          <Property Type="String" Name="LastName" Nullable="false" MaxLength="50" FixedLength="false" Unicode="true" />
          <Property Type="Int32" Name="ContactID" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
        </EntityType>
      </Schema>
    </edmx:ConceptualModels>
    <!-- C-S mapping content -->
    <edmx:Mappings>
      <Mapping Space="C-S" xmlns="urn:schemas-microsoft-com:windows:storage:mapping:CS">
        <EntityContainerMapping StorageEntityContainer="AdventureWorksModelStoreContainer" CdmEntityContainer="AdventureWorksEntities">
          <EntitySetMapping Name="EmployeeContacts">            
            <EntityTypeMapping TypeName="IsTypeOf(AdventureWorksModel.EmployeeContact)">              
              <MappingFragment StoreEntitySet="Employee">
                <Condition ColumnName="ContactID" IsNull="false"/>                
                <ScalarProperty Name="ContactID" ColumnName="ContactID"/>
                </MappingFragment>
              <MappingFragment StoreEntitySet="Contact">
                <ScalarProperty Name="ContactID" ColumnName="ContactID"/>
                </MappingFragment>
            </EntityTypeMapping>
            </EntitySetMapping>
          </EntityContainerMapping>
      </Mapping>
    </edmx:Mappings>
  </edmx:Runtime>
  <!-- EF Designer content (DO NOT EDIT MANUALLY BELOW HERE) -->
  <Designer xmlns="http://schemas.microsoft.com/ado/2007/06/edmx">
    <Connection>
      <DesignerInfoPropertySet>
        <DesignerProperty Name="MetadataArtifactProcessing" Value="EmbedInOutputAssembly" />
      </DesignerInfoPropertySet>
    </Connection>
    <Options>
      <DesignerInfoPropertySet>
        <DesignerProperty Name="ValidateOnBuild" Value="true" />
        <DesignerProperty Name="EnablePluralization" Value="True" />
        <DesignerProperty Name="IncludeForeignKeysInModel" Value="False" />
      </DesignerInfoPropertySet>
    </Options>
    <!-- Diagram content (shape and connector positions) -->
    <Diagrams>
      <Diagram Name="Model1" ZoomLevel="70">
        <EntityTypeShape EntityType="AdventureWorksModel.EmployeeContact" Width="1.5" PointX="3.25" PointY="0.5" Height="4.480205078125" IsExpanded="true" />
        </Diagram></Diagrams>
  </Designer>
</edmx:Edmx>

Answer 1

我有点放弃了这一点，意识到它似乎并不打算以这种方式使用。相反，我只会选择遍历导航属性，这就像做一个连接，除了更简单的OO方式。